Syringe



Feb. 10, 1953 N. s. WATERMAN SYRINGE Filed April 26, 1951 INVENTOR NEILS. WATERMAN ill a t ATTORNEY Patented Feb. 10, 1953 UNITED STATES PATENTOFFICE This invention relates to new and useful improvements insyringes.

An important object of this invention is toprovide syringes withsuperior aspiration. With normal syringes it is necessary that theneedle be engaged into the body and the plunger pulled back a smalldistance before it is pushed completely forward in order to test whetheror not a blood vessel has been pierced. If a blood vessel has beenreached and the plunger is pulled slightly back the blood will ooze outand be readily seen. If this occurs the needle must be drawn completelyout and a new spot located. Prior syringes, being collapsible tubes,make no provision for aspiration.

This invention proposes a new construction which makes it possible toimmediately determine whether the needle has pierced a vein withoutrequiring that the needle be drawn out a small distance, or otheroperation. Specifically, it is proposed that the syringe be constructedof transparent plastic or other transparent material and that anarrangement be provided which will permit the blood to flow through theneedle and be readily visible through the plastic if a vein is pierced.

Another object of this invention resides in the provision of openingscommunicationg with the atmosphere and formed in the body of the syringewhich will prevent the body from being air bound so that blood mayreadily flow through the needle and be visible if a vein is pierced. Itis also proposed that the plunger of the syringe be so arranged that itmay be forced downwards for ejecting the liquid of the syringe, and saidplunger should close the said openings immediately upon the slightestdownward motion of said plunger in order that the liquid may beentrapped and forced through the needle and into the body.

Another important advantage of the new syringe resides in the fact thatbecause it is constructed. of transparent material the liquid contentsmay be inspected to determine whether or not it is still fresh enough tobe used. Sediment or change of color of the liquid will easily be notedif the liquid has spoiled. In prior syringes inspection of the liquidwas not possible because the tubes used to hold the liquid were nottransparent.

Another important object of this invention resides in the provision of aresilient seal mounted across the bottom of the plunger of the syringeand arranged to hold the liquid in position adjacent the bottom of saidplunger. A novel construction is'proposed-for mounting the resilientseal on the plunger and for using the edge portion of the resilient sealas a seal between the sides of the plunger and the cylindrical body ofthe syringe.

Another object of the invention is the construction of a syringe asdescribed, which is simple and durable and which may be manufactured andsold at a reasonable cost.

For further comprehension of the invention, and of the objectsandadvantages thereof, reference will be had to the followingdescription and, accompanying drawing, and to the appended claims inwhich the various novel features of the invention are more particularlyset forth.

In the accompanying drawing forming a material part'of this disclosure:

Fig.1 is a vertical sectional enlarged view of a syringe constructed inaccordance with this invention.

Fig. 2 is a plan view of Fig. 1.

Fig. 3 is an elevational view of the plunger of the syringe shown inFig. 1.

Fig. 4 is an enlarged sectional view of the resilient seal used in thesyringe shown in Fig. 1.

Fig. 5 is an elevational view of the cylindrical body of the syringe.

Fig. 6 is a vertical sectional enlarged view of another syringeconstructed in accordance with a modified form of this invention.

The syringe illustrated in Figs. 1-5 inclusive, includes a cylindricalbody I0 having side walls II, an open top l2, 2. closed bottom I3, and ahollow steel needle I4 mounted through the closed bottom I3. A plungerI5 is slidably mounted in said cylindrical body I0 and is normallypositioned in the top portion of the body It). A resilient seal I6having an edge portion I! is. mounted around the bottom portion of saidplunger I 5 and engages against the inner face. of the body In forforming a liquid seal between.

the plunger I5 and the body Ill.

The resilient seal I6 has a bottom portion I6 extending across thebottom of the plunger I5 for holding a quantity of liquid I9 against thebottom of said plunger IS. The top end 20 of the needle I4 projectsupwards from the said closed bottom I3 of the body I0 and is normallyspaced a short distance beneath the bottom I8 of the seal I6. The topend 26 of the needle is adapted to pierce the said bottom it when theplunger I5 is moved downwards in order that said liquid I9 may then beforced through the needle I4 and out of thebottom end of the needle I4.The plunger I5 has a peripheral roove I 9" near its bottom end.

aeszesc Beneath this groove I9 there is a flange 20. The resilient sealI6 is formed with a groove 2| spaced downwards a short distance from itstop end. This groove 20 is adapted to receive and mate with the flange20 to connect the seal 16 with the plunger 15. The seal l6 has a flaredportion 22 above the groove 2| which will facilitate the engagement ofthe flange 20 of the plunger in the grooveZl. It is merely necessary to:force the flange downwards along the iiared portion 22 until it engagesin the groove 2|. The plunger i5 is formed with an enlarged top portion23 by which it may be easily held. Beneath this portion 23 there isthreaded portion 24 used to hold a cap 25 for the syringe in position. Awasher26 is interposed between the top edge 'of the cap '25 and theenlarged portion 23 of the plunger l5. The cap 25 enoases a portion ofthe plunger l5 and the entire cylindrical body Ill, including the needleM.

The side walls H of the cylindrical body iii are formed with openings 21at their top edges. These openings 21' are in the nature of slotsformed-downwards from the top edge of the body it. These slots 21 extenddownwards a very small distance to a point beneath a shoulder 23 formedexternally upon theresilient seal it while said plunger is in itsnormally raised position. The shoulder 28'isformed by reducing thediameter of the seal l6 -beneath said shoulder 23. The openings 21 willconnect the outside atmosphere, when the cap 25 is removed, with thespace 29 above the bottom of 'the body iii and beneath the seal I6.It'is proposed that the body it! and the plunger'lii be made'of stiffrigid type transparent plastic material, as styrene, which istransparent. The needle is may be made of steel. The resilient seal itshould be made of flexible, resilient and rigid type plastic materialsuch as polyethylene, which is translucent. The cap 25.may also be madeof stiff rigid type plastic material. The bottom of the plunger is isformed with a recess 30 into which the top '29 of the needle 14 mayengage when the plunger i5 is in its complete bottom position.

The operation of the device maybe understood from the following:

To use the syringe th 0111325 is first removed. Then the point of theneedle [,4 is inserted into aportion of a persons body. The inner end orthe needle 14 is observed to see whether blood starts entering the space,29 to determine if a vein has been pierced. The blood -may easily enterthe space 29'because the openings '2! in the body ill avoid air bindingthe spaeeifi. If a vein is pierced the needle id. is withdrawn and a newspot selected. If a vein has not been pierced the liquid i9 is injectedby merely forcing the plunger is downwards. The top end 29 of the needleM will pierce the bottom is of the .resilient seal .56 when the plungeris started downwards. Then further downward motion of the plunger [5will .iorce the'liquid 19 through the needle it. .Because the seal it ismade from resilient material and because it is a tight fit between theplunger I5 and the inner face of the body ID, the seal [6 will preventthe liquid is from coming out between the body 9 and plunger I5,insuring that the liquid 13 will be forced through the needle M.

Before the liquid "I9 is injected it may easily be inspected to seewhetheritis in good condition. If the color oftheliquid I9 has altered,or if the liquid l9 'hasbecome cloudy, or sedii ment has formed in it,the syringe is rejected and not used. The color of the liquid and thepresence of sediment may be seen through the bottom of the plunger .l5.

In Fig. 6 another form of the invention has been disclosed. This syringeincludes a cylindrical body 32 having side walls 33, an open top 34, aclosed bottom 35, and a hollow needle 35 mounted through the closedbottom 35. The side walls 33 are formed with openings 31 at its top edgeportion. A plunger 38 is slidably mounted in the cylindrical body 32 andis normally positioned in the top of the body 32. A resilient seal 39 ismounted across the bottom of the plunger 33. This seal 39 has an edgeportion 60 mounted around the bottom portion of the plunger 38 andengaging the inner face of the body 32 for forming a liquid seal betweenthe plunger 38 and body 32. The bottom portion of the seal 39 extendsacross the bottom of the plunger 38 and holds a quantity of liquid 4!against the bottom portion of the plunger 33. More particularly, thebottom portion of the plunger 38 is hollowed out forming a reservoir inwhich the liquid 4| engages. The cylindrical body 32 is formed with alarge projection 42 which is of the same shape as the said hollowed outportion of 'the plunger 38 so as to be capable of mating with the saidhollowed outportion when theplunger 3:; is forced downwards, and'in thisway eject all or the liquid ll through the needle 3%. The hollowed outportion of the plunger 38 is formed with a top recessed portion '43 intowhich the top of the needle 35 may engage when the plunger 38 is in itsextreme bottom position. The bottom portion of the seal 39 is adapted tobe pierced on the top end of the needle 36 when the plunger 38 is moveddownwards in order that the liquid 4| may be forced out from the bottomof the needle 35.

A cap 44 engages over the needle 38, over the body 32, and is threadedlyengaged upon a threaded portion :35 formed near the top of the plunger38. The plunger 33 has an enlarged top portion 35 by which it may beeasily gripped. .A washer ll! is engaged beneath the top portion 46 andthe top edge or" the cap 44. The openings 31 in the top portion of thebody 32 normally extend slightly beneath the bottom portion of the seal353 so that the space 58 between the bottom of the body 32 and thebottom of the plunger 38 is connected with atmosphere when the cap 44 isre moved. The bottom portion of the plunger 38 is formed with aperipheral groove intowhich the top portion iii of the resilient seal.39engages and by which the resilientseal 39 is mounted upon the bottomofthe plunger .38.

It is proposed that the plunger 33 and the body 32 be made from stifftransparent rigid type plastic material so that the space 48 and theliquid 1 may be inspected. The seal 39 is made from flexible andresilient rigid type plastic material such as polyethylene so that agood seal is formed between the plunger 38 and the cylindrical body 32when the plunger 38 is moved downwards in the cylindrical body 32.

The operation and use of this form of the invention is identical to theprior form.

While I have illustrated and described the preferred embodiments of myinvention, it is to be understood that I do not limit myself to theprecise constructions herein disclosed and the right is'reserved to allchanges and modifications coming within the scope of the invention asdefined in the appendedclaims.

Having thus described my invention, what I claim as new and desire tosecure by United States Letters Patent is:

1. A syringe, comprising a cylindrical body having side walls, an opentop, a closed bottom and a hollow needle mounted through said closedbottom. a plunger slidably mounted in said cylindrical body andnorm-ally positioned in the top of said body, a resilient seal having anedge portion mounted around the bottom portion of said plunger andengaging against the inner face of said body for forming a liquid sealbetween said plunger and body, said seal having a bottom portionextending across the bottom of said plunger for holding a quantity ofliquid against the bottom of said plunger, said bottom portion of saidseal being adapted to be pierced on the top end of said needle when saidplunger is moved downwards in order that said quantity of liquid may beforced out from the bottom of said needle when said plunger is moveddownwards, said body and plunger being transparent, and said side wallsof said body having in their top portions openings which extend belowsaid plunger when said plunger is in its initial raised position.

2. A syringe as defined in claim 1, in which said plunger is formed witha peripheral groove around its bottom portion, and said edge portion ofsaid seal engages said peripheral groove.

3. A syringe as defined in claim 1, in which said plunger is formed witha flange at its bottom and the edge portion of said seal is formed witha groove into which said flange engages for assisting in mounting saidseal around the bottom portion of said plunger.

4. A syringe as defined in claim 3, inwhich the edge portion of saidseal is flared above said groove to facilitate engaging said flange insaid groove.

5. A syringe as defined in claim 1, in which said plunger is formed witha reservoir in its bottom for accommodating said quantity of liquid, andsaid cylindrical body is formed with a projection on its closed bottomshaped to mate into said reservoir when said plunger is moved down insaid body.

6. A syringe as defined in claim 1, in which a cap encases said body,and said cap is removably mounted on said plunger.

NElL S. WATERMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 978,488 Roesch Dec. 13, 19101,456,469 Schwidetzky May 22, 1923 2,028,751 Barton Jan. 28, 19362,408,323 Lockhart Sept. 24, 1946 2,541,621 Thompson Feb. 13, 1951FOREIGN PATENTS Number Country Date 573,611 Great Britain Nov. 28, 1945

